1.1.2The Agreement requires the completion
of Environmental Impact Assessment (EIA) studies for the construction and
operation of two proposed permanent helipads: one at Peng Chau and one Yung
Shue Wan, Lamma Island.This report is
the Executive Summary for the proposed Peng Chau Helipad.

1.2.1The Project is ‘designated’ under Item
B.2, Schedule 2 of the EIA Ordinance (EIAO) by virtue of being: “A helipad within 300m of existing or planned
residential development”.Accordingly, an Environmental Permit is required for the Project.

1.2.2The
Project is required mainly by the Government Flying
Service (GFS) for transporting Peng Chau residents to urban areas for medical
treatment in emergency situations.The helipad may
also be used by GFS for training flights and for official Government visits.

1.2.3The current Peng Chau
helipad, located at the top of a hill, is not considered ideal by GFS on flight
safety grounds as the site is within a confined area and can only be accessed
by climbing long stairs.In view of the
present situation, the Home Affairs Department (HAD) commissioned CEDD to
construct the helipad for the local community.

1.3.2The Project location
and construction method were selected as the preferred options after due
consideration of each of 13 site options / alternatives [Figure 1.2]. Two sites were found to be either of insufficient
helicopter manoeuvring room or with unsuitable approach / departure paths and
so were not taken forward for detailed consideration. Table 1.1 presents a summary of the helicopter
site option evaluation for the remaining 11 sites that were evaluated after an
initial screening exercise.

1.4.1Measures incorporated into the Project
design to avoid / reduce environmental impacts include lowering the Project
elevation as far as practicable in order to minimize ‘footprint’ impacts, and
optimising the construction sequence to avoid cumulative noise effects with the
proposed construction of the Peng Chau Sewage Treatment Works Upgrade.

1.4.2As regards the operational Project,
helicopter noise is the main concern and in this regard the preferred site is
relatively remote from the built environment yet still readily accessible from
the local Clinic, while the angle of the helicopter flight path has been
reduced as far as was practicable to avoid / minimise noise effects on
residences.

1.5.1One other project identified in the
vicinity that requires consideration for the purposes of assessing cumulative
effects is the Drainage Services Department’s (DSD) Peng Chau Sewage Treatment Works (STW) Upgrade Project that is due
to commence construction in mid 2005.

1.5.2DSD is currently implementing sewerage
works at Peng Chau.It has been
confirmed with DSD that the portion of the works within the helipad Project
boundary were completed in 2004.

2.1.1Through proper implementation of dust
control measures as required under the Air
Pollution Control (Construction Dust) Regulation, construction dust can be
controlled to acceptable level and no significant impacts are anticipated with
the implementation of standard dust control measures.

3.1.1During the construction phase of the
helipad, Powered Mechanical Equipment used for the helipad construction will be
the primary noise sources.The key
noise generating activities include site clearance for the erection of site office, hoarding and fencing;
reclamation works, and construction of the helipad and EVA.

3.1.3Based on the construction schedule and
plant inventory given, the unmitigated construction noise level at Sea Crest Villa
is predicted to exceed the daytime noise standard of 75 dB(A).However, with the implementation of
appropriate mitigation measures, including use of silenced equipment and
temporary noise barriers, construction noise impacts can be reduced to an acceptable
level.

3.1.4The cumulative noise impacts arising
from the construction of helipad and sewage treatment works upgrade at Tai Lei
Island upon the common NSR has also been evaluated and no cumulative
construction noise impacts are anticipated.

4.1.1The sole noise source during the
operational phase of the Project will be from helicopter activities. At any one
time, the helipad may be used by either one of two helicopter types deployed by
Government Flying Service (GFS) for emergency casualty evacuation: Eurocopter Super Puma AS332 L2 and Eurocopter EC155 B1.

4.1.2Helicopter noise will be generated
when the helicopter is approaching and departing the helipad, and when it is
manoeuvring on and over the helipad (i.e., hovering over the helipad; touchdown
on the helipad; idling on the ground; and lift-off from the helipad surface to
achieve a hover).

4.1.3Based on the worst case scenario, the
maximum predicted helicopter noise level during manoeuvring for both helicopter models is within the Lmax limit and no
mitigation is required.During
helicopter approach the predicted noise level was initially 91 dB(A) and 88
dB(A) at NSR1 using the ‘Super Puma AS332 L2’ and ‘EC155 B1’ helicopters,
respectively.Accordingly, in
consultation with GFS, the angle of the flight path was reduced by 35 degrees,
resulting in approach mode noise from the ‘EC155 B1’ helicopter being within
the noise criteria of Lmax 85dB(A).

4.1.4There remains a maximum residual
impact of 3 dB(A) at NSR2 (Sea Crest Villa) during the approach mode for the
‘Super Puma AS332 L2’. However, with reference to actual ‘casevac’ helicopter
usage in Table 4.1, there will
normally be no residual impact as the ‘EC155 B1’ helicopter will be used
whenever possible. Use of the ‘Super Puma AS332 L2’ will be restricted to
special emergency situations when a larger capacity helicopter is
required.Furthermore, when use of the
‘Super Puma AS332 L2’ is necessary, the residual impact duration will be very
short (< 10 seconds).

1.The figures in brackets ( ) are the number of casevac flights carried
out by Super Puma (or Sikorsky prior to 2004).

2.Since 2003, all nighttime casevac has been undertaken using the EC155
B1 type helicopter only, although for the purpose of this noise impact
assessment it cannot be discounted that the Super Puma may be required for
nighttime casevac in future years.

3.Five casevac training flights were conducted to the Peng Chau helipad
in 2003 (i.e., an additional 2.3% of the total casevac flights).As no such data is available for other
years, the number of casevac training flights for 2000-2002 and 2004 have been
calculated using the same % contribution.It should be noted that GFS does not anticipate any increase in training
flights in the short to medium term as the helicopter fleet was upgraded in
2001/02 and there are no plans to add additional types of helicopters.

4.2.1The natural terrain of the cliff
adjacent to the helipad effectively controls manoeuvring noise from both
helicopter types, although noise levels from the approaching ‘Super Puma’ type
helicopter are predicted to exceed the Lmax 85 dB(A) limit at Sea
Crest Villa.As such, consideration was
given to direct mitigation involving relocation of the helipad a further 70
metres to the east [Figure 1.2; ‘Option
I’]. Ultimately, such relocation would encroach on to an area currently
zoned as a ‘Coastal Protection Area’ to protect and conserve the natural
shoreline, and would bring about landscape and increased ecological impacts,
including the complete loss of a sandy beach, as well as increased dredging
requirements and associated water quality impacts.

4.2.2A noise barrier is not practicable as
the approach noise impact arises when the ‘Super Puma’ type helicopter is in
mid-air over the sea, approximately 30 metres north of the helipad surface.

4.2.3Consideration was given to the
application of indirect mitigation measures that would require installation of
acoustic insulation into all NSRs at which the predicted Lmax exceeds
85 dB(A). Effective indirect mitigation would require that NSR residents comply
with a ‘closed-window’ living environment during helicopter manoeuvering.
However, it was considered that such measures would not be effective as
occupants of Sea Crest Villa would receive no prior notice of an impending
helicopter arrival, and because the noise impact duration would be so short
(< 10 seconds) the impact event would be over by the time a response could
be made.

4.3.2It should be noted that the existing
worst-case helicopter noise level at Sea Crest Villa exceeds the noise standard
by 4-7 dB(A) and there will be no spread of such noise impacts elsewhereafter implementing the proposed new helipad.Moreover, there are over 100 residential
building currently affected by the existing helipad.As such, the proposed new helipad will improve the ambient noise
environment.

4.3.3Residual noise may be audible during
night time from 7pm to 7am.Research
was undertaken to identify a suitable local or international standard to govern
helicopter noise at night.In accordance
with “Recommended Noise Reduction Approaches” in the United States of America Federal
Aviation Agency Hearings on [Non-military Helicopter Noise], the proposed use
of the new helipad for emergency use and noise from emergency medical
helicopter service is exempted and that emergency helicopter service is a
tolerable necessity.

4.3.4There is no standard on emergency
helicopter noise at night.Based on
Civil Aviation (Aircraft Noise) Ordinance (Cap 312) of Hong Kong, although
administrative means can be used to reduce the noise impact of the helipad
operations on the NSRs, restrictions such as limiting the number of helicopter
flights during night time as well as restrictions on the operating hours of the
helipad will not be practical as the use concerned is for emergency service,
which will be on an as needed basis that cannot be controlled.

4.3.5Best helicopter route over the least
densely populated areas will be used for the proposed new helipad.Considering that the helipad is for
emergency service and this is a tolerable necessity, the construction of the
helipad at the proposed location would therefore be acceptable.

4.3.6In addition, GFS has agreed to avoid
the use of the ‘Super Puma AS332 L2’ type helicopter whenever practicable,
although should the need arise, the local community may lodge noise complaints
with the Islands District Office by the following means: (Fax) 2815 2291;
(e-mail) dois@had.gov.hk; or (Post)
Islands District Office, Harbour Building, 20th Floor, 38 Pier road, Central.

5.1.1The waste management assessment
analysed the type of activities associated with the construction of the helipad
and the likely types of waste to be generated in order to outline measures to
minimize impacts to the surrounding environment and where possible to minimize
generation in the first place.It is
estimated that 14,000m3 of predominantly fine to coarse marine sand
will be dredged for disposal at the South Cheung Chau Spoil Disposal Area.Reclamation of approximately 30,200m3
of imported material will be required, of which approximately 25,000m3
will be rock fill and rock armour.

5.1.2Through
good practice and the mitigation measures that have been proposed for ensuring proper handling, storage, transportation and
disposal of various types of waste / materials throughout
the construction phase, no significant adverse impacts from waste management are anticipated.

5.2.1Organic (vegetation) waste is
anticipated to be the only form of waste generated due to the operation of the
helipad (from intermittent maintenance works).However, the volume of such waste is expected to be negligible, and no
adverse environmental impacts are anticipated during the operational phase.

6.1.1As only one dredger will be in
operation during the dredging works, calculations predict that elevations in
suspended solids at the identified sensitive receivers are negligible and well
within the tolerance level.It is also
predicted that the SS elevation will not exceed the tolerance level of 10.1
mg/l even in the very vicinity of the dredger, based on an average water depth
of 5.8m in the study area.The mixing
zone where the SS elevation will exceed the tolerance level is only 16m (along
the main flow direction) by 5m (normal to the flow direction) at a water depth
of 3m and 25m by 8m at a water depth of 2m, and will not affect water sensitive
receivers.

6.1.2As the backfilling material will be
rock armour and granular material with a minimum particle size of 20mm, no fine
sediment is expected to be released into water column during the backfilling
stage and this activity will have much less water quality impacts than the
dredging activities.

6.1.3The use of silt curtains will be used
to limit the extent of the impact zone.

6.2.1Hydrodynamic effects of the
constructed Project will be negligible, while there will be no operational
discharges that could potentially translate into impacts on the marine
environment.

7.1.1The Project requires approximately
14,000m3 of dredging covering a seabed area of approximately 0.57
ha. Of this area, approximately 0.33 ha of sub-tidal benthic habitat will be
permanently lost under the reclamation, with the remaining 0.24 ha temporarily
affected and available for recolonisation on completion of marine works.There will also be the permanent loss of
approximately 0.1 ha of mixed sandy, rocky and boulder inter-tidal habitat.

7.1.2As regards impact mitigation, a length
of approximately 200m of artificial sloping boulder seawall is to be
constructed that will provide some level of mitigation for the permanent loss
of natural habitat.Approximately 0.08
ha of sub-tidal benthic habitat and 0.12 ha of inter-tidal habitat can be
created, resulting in a net loss of some 0.25 ha of sub-tidal benthic habitat
and a net gain of some 0.02 ha of inter-tidal habitat.Given the low baseline ecological value of
the sub-tidal and inter-tidal habitats at Pak Wan, the residual impact is not
considered significant.

7.1.3The small scale and short duration of
the marine works will not cause any adverse water quality-induced impacts on
the hard coral community at east Tai Lei.Use of a silt curtain is recommended to contain water quality impacts,
and this will ensure no adverse ecological impacts on the hard coral
community.No significant terrestrial
ecology impacts are anticipated.

7.2.1Although the operational helipad will
be a source of noise when in use that has the potential to disturb birds and
potentially affect butterflies through air turbulence, no significant
ecological impacts are anticipated during the operational phase of the Project.

8.1.1While the Project will lead to the
permanent loss of approximately 0.33 hectares of shallow coastal environment,
the permanently affected area is not of any particular fisheries value being
situated in very shallow coastal waters.There is unrestricted fisheries habitat in adjacent waters contiguous
with the Project area, including undeveloped / undisturbed shallow coastal water
habitat east of the Project area.

8.1.2No significant water quality-induced
impacts are predicted in the popular fishing area off Tai Lei bridge given the
small scale of the dredging activities for the access road link, while there
are no impacts on the waters of this popular fishing area form the larger
dredging activity scheduled for the helipad footprint due to the greater
distance separation.

8.2.1The operational Project will not give
rise to any fisheries impacts, while there may be some fisheries benefits from
the construction of approximately 200m length of artificial seawall habitat.

9.1.1Marine geophysical survey at Pak Wan
identified two ‘items’ of potential marine archaeological value. However, due
to geophysical survey limitations imposed by the shallow water depth it was
decided to conduct a precautionary dive survey to cover these areas.

9.1.2The two items recorded detected by the
geophysical survey were identified as an area of coral rubble that was
deposited from the shoreline, and a boulder.Various small items were recorded form the dive survey in waters too
shallow for the geophysical survey boat, and these have been assessed to be of
minimal to low cultural heritage significance.No
further field investigation is recommended for the Peng Chau study area.

9.1.3Desktop and field evaluation of
terrestrial cultural heritage in and around the study area at Peng Chau
revealed that no archaeological sites, historic buildings or structures will be
impacted by the helipad development.

9.2.1The operational phase will not give
rise to any cultural heritage impacts.

10.1.1The Project involves the construction
and operation of a permanent helipad at Pak Wan, Peng Chau and is required
mainly for transporting Peng Chau residents to urban areas for medical
treatment in emergency situations. The Project will be constructed by
reclamation, and through site surveys and impact assessment no significant
adverse water quality or ecological impacts are anticipated from Project
construction or operation.

10.1.2The Pak Wan site was one of eleven
site options for the Helipad considered in detail, and was selected as the
optimal location for the Project due to its remoteness from the built
environment, while it is still easily accessible from the Peng Chau medical
clinic. The chosen helipad site offers the local community a significant time
saving compared with the existing helipad at Tai Lung Tsuen which is also predicted
to generate significant helicopter noise impacts (i.e., > 85 dB(A)) on
residents of over 100 village type and medium rise residential buildings,
including residents at Sea Crest Villa.

10.1.3The
helipad location also makes use of the natural rocky
cliff-face between the helipad surface and Sea Crest Villa to effectively
shield the residential development from helicopter manoeuvring noise, while the
helicopter flight path has been refined to eliminate approaching helicopter
noise impacts on residences under most operating conditions.

10.1.4While a residual helicopter noise impact is predicted during the approach
mode of the ‘Super Puma AS L2’ type helicopter, the impact frequency will be
approximately once every 12 days. The impact duration would last for less than
10 seconds per event, and the predicted magnitude, frequency and duration of
residual impacts would not give rise to serious long-term environmental
implications.